Orthopedic device having a dynamic control system

ABSTRACT

An orthopedic device is arranged to apply a dynamic load on a leg of a user. The orthopedic device has a rigid or semi-rigid frame including lower and upper frames, and a hinge assembly connecting the lower and upper frames. A dynamic loading component is used to urge the load on the user&#39;s leg on the basis of flexion of the hinge assembly on the basis of tension in an elongate element connecting the dynamic loading component and at least one of the lower and upper frames. A peak load is generated at a flexion angle between extension and maximum flexion of the hinge assembly.

FIELD OF THE DISCLOSURE

This disclosure relates to an orthopedic device having a dynamic controlsystem for providing variable assistance during gait, particularly as auser flexes a knee, and generally providing increased loading at certainflexion angles and diminished loading at other flexion angles andextension.

BACKGROUND

There are roughly 200,000 partial or complete anterior cruciate ligament(“ACL”) injuries per year in the U.S. The ACL is an intracapsularligament that is unable to spontaneously heal complete tears.Approximately 50% (100,000 U.S. patients) of ACL injuries go untreatedeither through a lack of diagnosis or repair is deemed unnecessary dueto the patient's low level of activity.

Partial ACL tears may heal spontaneously but may heal at an increasedlength resulting in a positive “Drawer Test” (a commonly used test todetect the rupture of cruciate ligaments in the knee) and the ability ofthe tibia to shift anteriorly regarding the femur. In the Drawer Test,if the tibia pulls forward or backward more than normal, the test ispositive. Excessive displacement of the tibia anteriorly indicates theACL is likely torn, whereas excessive posterior displacement of thetibia indicates the PCL is likely torn. Complete ACL tears that gounrepaired will cause a positive Drawer Test.

Some surgeons show positive results in healing for some patients withACL injury through minor surgical intervention by reattaching the ACL.

For the remaining 100,000 patients who undergo ACL repair for completetears, some studies have shown the strength of the ACL ligament isreduced to approximately 50% of its original strength 6 months aftersurgery. This may be due to the revascularization of the ACL ligament.At six months, these patients often feel stable enough to return totheir previous level of activity. This places the ACL at risk becausethe patient does not realize the ACL is only at 50% of its originalstrength.

During normal activity, tension on the ACL may vary. Activities thatrequire sudden stops and changes of direction may place high tension onthe ACL or create displacement of the tibia regarding the femur.Adjustment of the tibia relative to the femur, and possibly reduction ofACL tension could benefit the patient in the following ways: (1) reduceadditional injury and preserve the length of the partially torn ACL, and(2) reduce the risk of reinjury of the graft for the ACL repairedpatient.

SUMMARY

According to various exemplary orthopedic device embodiments of thedisclosure, an orthopedic device may take the form of a knee bracepreferably providing a dynamic posteriorly directed force on theanterior tibia or dynamic anteriorly directed force on the posteriorfemur. The brace has a rigid or semi-rigid frame including lower andupper frames, and a hinge assembly that connects the lower and uppercomponents.

With the embodiments, loading on the leg, whether the femur or tibia,and on either posterior or anterior sides, is generally achieved atincreased amounts depending on peak angles and diminished amountsoutside the peak angles. The reduced loading outside the peak angles ispreferably gradual, and is achieved by means interacting with a hingearticulating from extension to flexion and vice versa.

A dynamic loading component, such as a femoral or tibial shell, is usedto alter the femur relative to the tibia with an adjustment device.According to an embodiment, the dynamic loading component may beflexible relative to the brace frame and is connected to the lowercomponent to move posteriorly toward a user's tibia, particularly inrelationship to the lower component. A variable clearance is definedbetween the tibial shell and the lower frame. An adjustment device isarranged for regulating the degree to which the tibial shell isinitially drawn to the anterior tibia. The adjustment device has anelongate element that connects the tibial shell to the hinge. The tibialshell may be moved toward the lower frame by reducing a width of thevariable clearance. The adjustment device couples to the hinge assemblysuch that the tibial shell is urged inwardly toward the lower frame asthe knee undergoes flexion and extension from articulation of the hingeassembly.

In a variation, the dynamic loading component may be rigid orsemi-rigid, and is not limited to being flexible. The dynamic loadingcomponent, although described above as moving the tibia, may be placedabove the hinge and on the posterior side of the orthopedic device so asto connected to the upper frame.

The elongate element secures to the hinge to encourage greater tensionin the elongate element as the brace is flexed and extended. Theadjustment device may have first and second elongate elements eachextending from first and second sides, respectively, of the adjustment.The adjustment device may be adapted for simultaneously regulating thelength of the first and second elongate elements. The elongate elementmay extend laterally from the adjustment device to at least one of thelateral or medial sides of the lower frame. A guide element may bearranged to longitudinally route the at least one elongate element alongthe lower frame toward the hinge assembly.

The orthopedic device may include a cam assembly coupling to the hingeassembly. In an embodiment, the cam assembly includes a cam plate and acam follower for engaging the cam plate connected to a lower strutbelonging to the lower frame. The at least one elongate elementconnecting to the cam follower to enable a variable force to be exertedby the tibial shell on the basis of travel of the cam follower andtension created in the at least one elongate element due to resistanceagainst a user's tibia by the tibial shell. Of course, the cam assemblycan be arranged on the upper strut should the dynamic loading componentbe placed on the upper, posterior side of the orthopedic device.

The cam plate may define an eccentric shape including at least twosegments arranged in different directions: a first segment extendinggenerally linearly and the second segment extending generally arcuately.The cam plate may define an eccentric shape arranged to urge the tibialor femoral shell toward the lower or upper frame at a greatest forcegenerally between 10 to 40 degrees flexion of the hinge assembly byreducing the variable clearance and/or creating tension in the elongateelement. The cam assembly may be arranged to urge an increasing force toa maximum force within the range of 10 to 40 degrees of flexion of thehinge assembly.

A guide block may be secured to the lower strut and the cam follower maybe arranged to slidably engage the guide block depending on therelationship of the cam follower to the cam plate. The cam follower mayinclude a piston arranged to slide longitudinally within a slot definedby the guide block.

The hinge assembly may be provided by itself for attachment to anorthopedic device and include a first strut, a second strut pivotallyconnected to the first strut, and a cam assembly including a cam platehaving a guide slot with a shape and pivotally attached to one of thefirst and second struts, and a cam follower adapted to engage the guideslot to travel along the guide slot shape. A block may be arranged onone of the first and second struts and adapted to receive the camfollower arranged to piston within the block. The hinge assembly mayalternatively have the features described in connection with the hingeassembly and cam assembly of the orthopedic device embodiments.

A method provides variable assistance during gait and may include thesteps of providing any of the embodiments and variations of theorthopedic device on a leg of a user with the orthopedic having a shelladapted to apply pressure against a lower leg of a user. The methodinvolves urging a posteriorly directed force against an anterior tibiaof a user during an initial stage of flexion of a leg. The method mayyet further include diminishing the posteriorly directed force after theinitial stage of flexion. The method may also include initially settinga predefined force at a predetermined angle of flexion before a user'sknee undergoes range of motion.

The tibial shell may be arranged to apply a greater posteriorly directedforce against an anterior tibia of a user during the initial stage offlexion of the leg and during the final stage of extension of the leg.As force applies to the anterior tibia, anterior tibia shift regardingthe femur is neutralized or minimized due to the posterior force. As theleg continues to be extended after the initial stage of flexion, theposteriorly directed force increases up to a peak load and thendiminishes after peak load to full extension. The initial tension in theelongate element may be set by a clinician based on a user's individualload requirement, and the adjustment device may be temporarily lockedafter the initial load is set.

The dynamic loading component can be arranged posteriorly above the kneeso that it is arranged on the distal posterior thigh of a user so as notto impinge on a user's popliteal. In this embodiment, posterior dynamiccompression from the dynamic loading component urges the femur anteriorrelative to the tibia similar in the manner the tibial shell urges theposterior relative to the femur, and basically produces the same dynamicload to assist users with impaired knee ligaments.

In a variation, the uprights may include a cutout to urge a load more ina saggital plane rather than a coronal place. This enables a cable toextend more saggitally and more loading of the posterior femuranteriorly or loading of the anterior tibia posteriorly. It has beenfound that medial collateral ligament injuries are often concurrent withACL injuries and therefore reduction of the coronal (medial/lateraldirections) pressure minimizes contact pressure on such surgicalregions.

Various hinge assemblies may include a cam assembly having a cam surfaceand cam follower connected to the hinge assembly and arranged to createpeak tension at a peak angle generating tension in the cable. Moreover,routing parts can be used to reduce slack in the cable and therebymaintain tension and remain at cable tension during flexion toextension.

The numerous other advantages, features and functions of embodiments ofan orthopedic device will become readily apparent and better understoodin view of the following description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawing figures are not necessarily drawn to scale, but instead aredrawn to provide a better understanding of the components thereof, andare not intended to be limiting in scope, but rather to provideexemplary illustrations. The figures illustrate exemplary configurationsof an orthopedic device, and in no way limit the structures orconfigurations of a liner according to the present disclosure.

FIG. 1 is a front elevational view showing a first embodiment of anorthopedic device having a dynamic control system.

FIG. 2 is a side elevational view showing the embodiment of FIG. 1.

FIG. 3 is a schematic side elevational view showing the orthopedicdevice according to FIG. 1 on a leg in a fully extended position.

FIG. 4 is a schematic side elevational view showing the orthopedicdevice according to FIG. 1 on a leg during an initial stage of flexion.

FIG. 5 is a perspective view of a hinge assembly according to theembodiment of FIG. 1.

FIG. 6 is an exploded view of the hinge assembly of FIG. 5

FIG. 7 is a front elevational view of the hinge assembly of FIG. 5.

FIG. 8 is a rear elevational view of the hinge assembly of FIG. 5.

FIG. 9 is a side elevational view of the hinge assembly of FIG. 5.

FIG. 10 is a graph depicting the force applied to an ACL versus itsflexion angle as a knee is flexed.

FIG. 11 is a sectional view showing another hinge assembly embodiment.

FIG. 12 is a sectional view showing another hinge assembly embodiment.

FIG. 13 is a sectional view showing another hinge assembly embodiment.

FIG. 14 is a side elevational view showing an orthopedic device havinganother hinge assembly embodiment.

FIG. 15 is a side elevational view showing an orthopedic device havinganother hinge assembly embodiment.

FIGS. 16A and 16B show views of comparing different hinge assemblyembodiments.

FIGS. 17A-17C show views comparing different angles of a hinge assemblyembodiment.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS A. Overview

A better understanding of different embodiments of the disclosure may behad from the following description read with the accompanying drawingsin which like reference characters refer to like elements.

While the disclosure is susceptible to various modifications andalternative constructions, certain illustrative embodiments are in thedrawings and are described below. It should be understood, however,there is no intention to limit the disclosure to the specificembodiments disclosed, but on the contrary, the intention covers allmodifications, alternative constructions, combinations, and equivalentsfalling within the spirit and scope of the disclosure.

It will be understood that, unless a term is expressly defined herein topossess a described meaning, there is no intent to limit the meaning ofsuch term, either expressly or indirectly, beyond its plain or ordinarymeaning.

Any element in a claim that does not explicitly state “means for”performing a specified function, or “step for” performing a specificfunction is not to be interpreted as a “means” or “step” clause asspecified in 35 U.S.C. §112, paragraph 6.

B. Definitions

For ease of understanding the disclosed embodiments of an orthopedicdevice, the anterior and posterior portions of the orthopedic device maybe described independently. Anterior and posterior portions of theorthopedic device function together to support and stabilize anatomicalportions of the user of the device.

For further ease of understanding the embodiments of an orthopedicdevice as disclosed, a description of a few terms, when used, isnecessary. As used, the term “proximal” has its ordinary meaning andrefers to a location situated next to or near the point of attachment ororigin or a central point, or located toward the center of the body.Likewise, the term “distal” has its ordinary meaning and refers to alocation situated away from the point of attachment or origin or acentral point, or located away from the center of the body. The term“posterior” also has its ordinary meaning and refers to a locationbehind or to the rear of another location. Lastly, the term “anterior”has its ordinary meaning and refers to a location ahead of or to thefront of another location.

The terms “rigid” and “flexible” may distinguish characteristics ofportions of certain features of the orthopedic device. The term “rigid”should denote an element of the device is generally devoid offlexibility. Within the context of frame or support members or shellsthat are “rigid,” it is intended to indicate that they do not lose theiroverall shape when force is applied, and they may break if bent withsufficient force. The term “flexible” should denote that features arecapable of repeated bending such that the features may be bent intoretained shapes or the features do not retain a general shape, butcontinuously deform when force is applied.

As for the term “semi-rigid,” this term is used to connote properties ofsupport members or shells that provide support and are free-standing;however such support members or shells may have some degree offlexibility or resiliency.

C. Various Embodiments of the Orthopedic Device

According to an embodiment illustrated in FIGS. 1 and 2, the orthopedicdevice is a knee brace including a dynamic load control system. Thedynamic load control system has a hinge assembly or adjustment device100 configured for attachment to lower and upper components 12, 14 forsecuring the brace onto a user's leg below and above the knee,respectively. The hinge assembly 100 advantageously provides dynamicforce adjustment to the knee brace 10, especially in neutralizingundesired forces on a patient's ACL in the anterior and posteriordirections.

The knee brace 10 has a rigid or semi-rigid frame including the lowerand upper components 12, 14 preferably but not limited to beingconnected to one another by the hinge assembly 100 on both the medialand lateral sides of the brace. Lower and upper straps 22, 24 may extendfrom the lower and upper components 12, 14 for securing the brace onto auser's leg below and above the knee, respectively. The knee brace framemay take on many shapes, such as those shown and described in U.S. Pat.No. 5,230,697, granted Jul. 27, 1993, U.S. Pat. No. 8,048,013, grantedon Nov. 1, 2011, and U.S. patent application publication 2012/0046585,published on Feb. 23, 2012, each of which are incorporated by referencein their entirety.

According to the device, a dynamic loading component is movablyconnected to the lower component 12. In this embodiment, the dynamicloading component is preferably a tibial shell 32, however the dynamicloading component can be rearranged as a femoral shell for loading thefemur rather than the tibia. The tibial shell 32 preferably includesfirst and second wings 33A, 33B adapted to yield in part over a tibia ofa user. The tibial shell 32 also includes a central portion 33C fromwhich the first and second wings 33A, 33B extend.

An adjustment device 18 is mounted on the tibial shell 32 preferably atthe central portion 33C by a plate 30 arranged to stably secure theadjustment device 18 on the subshell 32. The adjustment device 18includes one or more elongate elements 26 and is regulated the length ofa segment of the elongate element 26 extending from the adjustmentdevice 18. It should be appreciated, however, that the adjustment devicemay alternatively be secured elsewhere on the brace.

The adjustment device 18 regulates the length of one or more elongateelements 26 between the adjustment device 18 and the lower frame 12, andmoves or attempt to move the tibial shell toward the lower frame 12 byreducing a width of a variable clearance 31 between one of the first andsecond wings 33A, 33B. Maybe the clearance does not modify or adjustduring movement of the hinge assembly from extension to flexion, butrather the distance or tension of the at least one elongate element ismaintained or increased as the hinge assembly moves, to maintain orincrease pressure or force exerted on the tibia by the tibial shelldepending certain position of flexion.

The adjustment device may be a dial tensioning device provided by BOATechnology Inc., or an adjustment device described in U.S. Pat. No.7,198,610, granted Apr. 7, 2007, and U.S. patent application publicationno. 2009/0287128, published Nov. 19, 2009, which are incorporated byreference and belong to the assignee of this disclosure.

The tibial shell 32 is secured to the lower component 12 by anchors 38(FIG. 2) securing the elongate elements 26 to the brace. The elongateelements 26 tether the tibial shell 32 to the lower component 12 whilepermitting movement of the tibial shell relative to the lower component.Suitable padding may also be provided along various portions of the kneebrace including along the lower and upper components, and the subshell.

As with any other embodiments described, the adjustment device 18 mayinclude indicia that allows for an understanding as the adjustmentdevice is regulated. The clinician may initially set the adjustmentdevice, and the adjustment may be locked to provide consistent dynamicadjustment over extension and flexion. Alternatively, the user mayregulate the adjustment device as needed.

In this embodiment, two segments of the elongate element 26A, 26B extendfrom opposed sides, such as lateral and medial sides, of the adjustmentdevice 18. The segments 26A, 26B extend along the lower component 12 andmay be aided by guides located thereon. The anchors 38 may also helpguide the segments 26A, 26B along the brace in the direction toward thehinge 100. The segments 26A, 26B are additionally secured to the hingeassembly 100, as will later be discussed. While the path of the segments26A, 26B along the lower component to the hinge is generally in asymmetrical configuration on the lateral and medial sides of the brace,it will be understood that the segments 26A, 26B may be arranged indifferent paths relative to one another in variations of the brace. Theelongate element may be a cable, lace or other suitable elongate elementthat can be regulated in length extending from the adjustment device.

FIG. 3 shows the knee K in full extension E, whereby the upper leg ULand the lower leg LL are in a generally straight configuration. When inextension, the tibial shell 32 exerts a posteriorly directed force PFagainst the anterior tibia to urge the tibia posteriorly, particularlysince the elongate element 26 is taut in view of the relative positionof the lower component relative to the upper component and biased by thehinge 100. The tibial shell assists an injured ACL by preventing thetibia from advancing anteriorly when the knee is in extension E.

FIG. 4 shows the knee K in an initial stage of flexion F, whereby thelower leg LL and upper leg UL are arranged at an angle relative to oneanother such that the knee K is bent. The arrangement of the hinge 100causes tension in the elongate element 26 to increase during the initialstage of flexion, and then return to its original tension level as theknee continues to be flexed. This way the posterior force PF issubstantially more when the knee is initially flexed as opposed to whenthe knee is fully extended.

As illustrated in FIGS. 5-9, an embodiment of the hinge assembly 100comprises a rigid frame including an upper strut 110 having an upperpivot end 112 and an upper support end 114, and a lower strut 120 havinga lower pivot end 122 and a lower support end 124. In a preferredembodiment the upper and lower struts are substantially flat, however,they may have other shapes such as curved to anatomically accommodate auser's leg and/or movement. The upper and lower struts are pivotallyconnected at each respective pivot end by a first pivot member 116defining a hole formed on the upper strut for pivotally engaging asecond pivot member 126 defining a corresponding protrusion formed onthe lower strut. The first pivot member 116 may be shaped to pivotallyreceive the second pivot member 126 such that each strut maintains a lowprofile when connected.

The upper support end 114 of the upper strut 110 is configured forattachment to the upper component 14 of the brace, and the lower supportend 124 of the lower strut 120 is configured for attachment to the lowercomponent 12 of the brace.

The hinge assembly 100 further comprises a cam assembly 101 including acam plate 130 pivotally attached at a pivot portion 132 to the lowerpivot end 122 of the lower strut 120 by a fastening member 140. In apreferred embodiment the cam plate is generally flat, although it may becurved or arranged in other forms to accommodate movement of a knee. Thefastening member is preferably configured to fixedly secure the camplate 130 to the upper pivot end 112 of the upper strut, so the lowerstrut 120 may pivot about both the cam plate 130 and the upper strut 110at the lower pivot end 122. The fastening member may include a bolthaving a partially threaded shank.

It will be understood the hinge assembly 100 is not limited to thesingle axis hinge structure depicted and discussed herein for couplingthe upper and lower struts 110, 120. A wide variety of types of hingesmay used to couple the upper and lower struts, including but not limitedto four-bar hinges of the type described in U.S. patent applicationpublication nos. 2012/0059296, published on Mar. 8, 2012, 2013/0331754,published on Dec. 12, 2013, incorporated herein by their entirety,polycentric hinges of the type described in U.S. patent applicationpublication no. 2004/0002674, published on Jan. 1, 2004 incorporatedherein by its entirety, and U.S. Pat. No. 7,198,610, and other types ofknown hinges used in the art of knee bracing.

The lower pivot end 122 of the lower strut 120 further defines athrough-hole 128 axially extending through both the second pivot member126 and the lower strut, and which is adapted to receive the fasteningmember 140. An accompanying retaining member 150, such as a washer, mayhelp retain the fastening member to the upper strut 110. This allows thefastening member to fixedly secure the upper strut 110 to the cam plate130, with the lower strut 120 pivotally coupled between both the upperstrut and the cam plate.

A guide block 160 having a substantially flat first surface 162 isfixedly secured to an intermediate portion 123 of the lower strut 120and located adjacent to the cam plate 130. A second surface 164 on aside of the guide block 160 opposed to the first surface 162 defines alongitudinal groove or slot 166 for movably connecting to and guiding afirst end 182 of a piston 180 to permit longitudinal movement B. Asecond end 184 of the piston 180 is configured to extend beyond theguide block 160 in a direction toward the pivot portion 132 of the camplate 130 and is fixedly secured to a guide member 190.

The guide member 190 is retained within an eccentric guide slot 134formed on the cam plate 130 and is adapted to move in the direction ofthe guide slot. The combination of the piston 180 and the guide member190 affixed thereto form a cam follower 170. The guide member 190correspondingly moves within the guide slot 134 as the lower strut 120is pivotally rotated relative to both the upper strut 110 and the camplate 130 urging the piston 180 either toward or away from the pivotportion 132 of the cam plate as it follows the eccentric shape of theguide slot.

Preferably, the eccentric shape of the guide slot 134 is configured suchthat when the guide member 190 reaches a first end 136, the upper andlower struts 110, 120 are longitudinally aligned for supporting thebrace in a fully extended position. Conversely, when the guide member190 engages a second end 138 of the guide slot 134, the upper and lowerstruts 110, 120 are pivotally positioned relative to each other forsupporting the brace in a fully flexed position. The cam follower 170may also act as a pivot limiter by preventing the lower strut frompivoting relative to both the upper strut and the cam plate beyond a setposition in either extension or flexion.

The eccentric guide slot 134 provides dynamic control to the forceapplied to the user's tibia in the posterior direction. The shape of theguide slot is further configured such that the cam follower 170 isbriefly urged from an original, or neutral, position toward the pivotportion 132 of the cam plate 130 during the initial stage of flexion ofa patient's knee, and then returned back to its original position forthe duration of flexion. Similarly, such a configuration also ensuresthat the cam follower 170 is briefly urged from an original, or neutral,position toward the pivot portion 132 of the cam plate 130 during thefinal stage of extension of a patient's knee and then returned back toits original position once fully extended.

Each segment 26A, 26B of the elongate element is securely coupled to arespective hinge assembly by a connector 186 at the first end 182 of thepiston 180. The connector 186 may include apertures for tying theelongate element thereto. The initial tension in each segment 26A, 26Bof the elongate element is set by the adjustment mechanism 18. As thecam follower 170 is pulled toward the pivot portion 132 of the cam plate130, the elongate element is likewise pulled taut increasing the tensionin the elongate element. This increase in tension correspondingly causesthe tibial shell 32 to exert additional posteriorly directed forceagainst the anterior tibia to urge the tibia posteriorly.

The aforementioned known hinge structures may be in combination with thecam assembly whereby the cam plate is secured to a hinge component orthe upper frame or strut and the cam follower secures to the lower frameor strut. Regardless as to the type of hinge structure employed, the camassembly tracks the articulation of the upper strut relative to thelower strut and enables selective and dynamic control of the elongateelement and the tibial shell.

In referring to FIG. 10, a graph shows the loading on a patient'sinjured ACL and its corresponding angle of flexion. The bottom curvedenotes the force on an average ACL during rehabilitation exercises, andthe top curve denotes the force on a worst case ACL drop landing. Theloading is plotted against the angle of flexion of a patient's knee.From these curves, peak loading occurs in both situations during theinitial stage of flexion, making it the most dangerous.

Extension generally occurs at 0 degrees with the leg and orthopedicdevice in a fully or substantially upright formation. As the hingeassembly articulates, the orthopedic device undergoes flexion over aplurality of angles. Maximum flexion is referred to herein at about 135degrees, however, flexion may still continue to occur past 135 degreesas shown in FIG. 10, and may vary from individual to individual. Theforce required may gradually increase past 90 degrees after havingdiminished approaching 90 degrees as the maximum flexion serves in partas an inflection point on the curve shown in FIG. 10.

The eccentric shape of the guide slot 134 of the cam plate 130 ispreferably provided up to twenty degrees of additional tensioning in theelongate element 26 during the most dangerous stage of flexion andextension of a patient's knee. The eccentric shape of the guide slot 134ensures that the additional posteriorly directed force is applied by thetibial shell only during the initial stage of flexion and the finalstage of extension of a patient's knee. This posteriorly directed forceexerted by the tibial shell would advantageously neutralize the ACLforce in the anterior direction by resisting movement of the tibiatoward the anterior direction relative to the femur at its mostvulnerable angles.

In referring to the shape of FIG. 6, the shape of the guide slot 134involves a first segment 137 encompassing the first end 136. The firstsegment 137 extends upwardly or toward the upper strut 110 at an obliqueangle generally extending toward the posterior side P of the hingeassembly relative to an axis A-A representing extension of the hingeassembly. The first segment 137 is arranged to generally correspond toapproximately 0 to 15 degrees of flexion, as corresponding to the slopein FIG. 10 to generate force. The first segment 137 may extend generallylinearly from the first end 136 to a transition segment 141 of the guideslot.

The transition segment 141 generally corresponds from 10 to 40 degreesof flexion so as create an increase in force and then taper in force asthe hinge assembly goes into greater flexion. The guide slot 134includes a second segment 139 encompassing the second end 138 andrepresenting a diminution in force generated as the knee goes intogreater flexion as the cam follower travels to the second end 138. Thesecond segment 139 generally extends arcuately from the transitionsegment 141, which is arranged to smooth the transition between thepaths of the first and second segments 137, 139.

Another hinge assembly or adjustment device embodiment 200 is depictedin FIG. 11. This hinge assembly relies on using “follower” tracks with acam assembly and a follower defined along the periphery of a hingeelement, such as a plate. The cam assembly mimics the load curve asgenerally referred in FIG. 10 to increase and decrease a load incombination with a cable and a dynamic shell depending on the degree offlexion. The dynamic loading component can load the tibia or the femurdepending on the orientation of the cam assembly and the cam follower.

The hinge assembly 200 includes a polycentric hinge 202 having first andsecond pivot points 204, 206, and a hinge element 208, preferablydefined as a hinge plate. The hinge element 208 defines a cam surface210 arranged to mimic the load curve defined in FIG. 10. A peak 212defined by the cam surface 210 represents the maximum load exerted bythe dynamic loading component 227, whereas the sloping segments 214, 216represent gradually changing loads extending from the peak load 212.

The hinge assembly includes first and second struts 218, 220 connectingto the hinge 202. The first and second struts 218, 220 may be formedfrom an orthopedic device frame, or the first and second struts 218, 220may secure to upper and lower frames, such as those in FIG. 1.

A cable 222 connects at one end to the dynamic loading component 227,extends and is routed through a cable guide 226 to a cable anchor 234carried by the cam assembly 228. In this embodiment, the cable 222extends over the hinge 202 and moves relative thereto according to theangle of flexion the hinge undergoes. The cam assembly 228 includes acam follower 230 arranged to move and engage the cam surface 210. Thecam assembly 228 is pivotally mounted on the upper strut 220 by a pivotelement 232 to accommodate movement of the hinge 202 and the camfollower 230 relative to the cam surface 210.

The cam assembly 228 includes a plate 229 carrying the cam follower 230,the pivot element 232 and the cable anchor 234. The plate 229 defines anarm 235 extending from the pivot element 232 and defining a plurality ofopenings 233 for variable placement of the cable anchor 234 fordifferent predetermined tension settings of the cable 224.

FIG. 12 represents an adjustment device or hinge assembly embodiment 300that is a variation of the hinge assembly 200 of FIG. 11. The hingeassembly 300 includes a polycentric hinge 302 and first and second pivotpoints 304, 306. The hinge 302 includes a hinge element 308, preferablydefined as a hinge plate. The hinge element 308 defines a cam surface310 arranged to mimic the load curve defined in FIG. 10. For example, apeak 312 defined by the cam surface 310 represents the maximum loadexerted by the dynamic loading component (not shown), whereas thesloping segments 314, 316 represent gradually changing loads extendingfrom the peak load 312.

The hinge assembly 300 includes first and second struts 318, 320connecting to the hinge 302. The first and second struts 318, 320 may beformed from an orthopedic device frame, or the first and second struts318, 320 may secure to upper and lower frames, such as those in FIG. 1.

A cable 322 connects at one end to the dynamic loading component (notshown, but using the guide of FIG. 11 as an example), extends and isrouted through a cable guide (not shown, but using the guide of FIG. 11as an example) to a cable anchor 334 carried by a cam assembly 328. Inthis embodiment, the cable 322 extends over the hinge 302 and movesrelative thereto according to the angle of flexion the hinge undergoes.The cam assembly 328 includes a cam follower 330 arranged to move alongand engage the cam surface 310. The cam assembly 328 is pivotallymounted on the upper strut 320 by a pivot element 332 to accommodatemovement of the hinge 302 and the cam follower 330 relative to the camsurface 310.

The cam assembly 328 includes a plate 329 carrying the follower 330, thepivot element 332 and the cable anchor 334. The plate 329 defines an arm335 extending from the pivot element 332 and defining a plurality ofopenings 333 for variable placement of the cable anchor 334 fordifferent predetermined tension settings of the cable 322.

The hinge assembly 300 includes first and second routing parts 350, 352extending from the hinge element 308. In a preferred embodiment, therouting parts 350, 352 include a washer and fastener, as depicted inFIG. 12, although other types of routing parts are envisioned andcapable of routing the cable over the hinge element. The cable 322extends about the routing parts 350, 352 and forms an “S” shaped cablepath, although other shaped paths are envisioned.

The cable path about the routing parts forms a “zero-slack” pathallowing the cable to be tensioned and remain in tension during flexionto extension. This arrangement permits achieving the desirable limit orthreshold loading at extension. The cam assembly and hinge elementprofile allow for tension in the cable to ramp up to a maximum load at apredetermined flexion angle and then reduce in load after the peak isachieved.

FIG. 13 shows another hinge assembly or adjustment device embodiment400. The hinge assembly 400 includes a polycentric hinge 402 and firstand second pivot points 404, 406. The hinge 402 includes a hinge element408 upon which the first and second pivot points 404, 406 are located.

As with other hinge assembly embodiments, the hinge assembly 400includes first and second struts 418, 420 connecting to the hinge 402.The first and second struts 418, 420 may be formed from an orthopedicdevice frame, or the first and second struts 418, 420 may secure toupper and lower frames, such as those in FIG. 1.

A link 422 connects at one end to a cable anchor 434 and extends to amultiplier element 426. The multiplier element 426 is arranged toincrease the amount of tension in a cable extending to the dynamicloading component 438. The link 422 may be a cable, strut, or otherdevice connecting to the multiplier element 426. The multiplier element426 is preferably pivotably mounted on the first strut 418 and ispivotable relative to the hinge 402.

In a variation, the multiplier element may be arranged to yield underpredetermined loads to prevent excessive loads exerted by the dynamicloading component. For example, it may be constructed from a plasticthat will bend or yield at a certain load so as to serve as a safeguardagainst overloading by the dynamic loading component.

The hinge element 408 and the upper strut 420 in a polycentric hingemove at different angular rates when compared to the lower strut 418.Because the hinge element 408 moves at half the angular distance as theupper lower strut for a 90 degree motion (sitting to standing), theL-shaped of the multiplier element serves as a multiplier to increasethe amount the cable 422 pulls. The peak cable tension may be achievedgenerally when the cable path passes over the lower pivot 404.

FIG. 14 illustrates a hinge assembly or adjustment device 500 on anorthopedic device 554. Similar to other hinge assembly embodiments, thehinge assembly 500 includes a polycentric hinge 502 and first and secondpivot points 504, 506. The hinge 502 includes a hinge element 508 uponwhich the first and second pivot points 504, 506 are located. The hingeassembly 500 includes first and second struts 518, 520 connecting to thehinge 502. The first and second struts 518, 520 may be formed from anorthopedic device frame, or the first and second struts 518, 520 maysecure to upper and lower frames, such as those in FIG. 1.

A cable 522 connects at one end to the dynamic loading component 538,extends and is routed through an elongate portion 527 of a cable guide526 to a cable anchor 534 carried by the second strut 520. The cable 522is arranged to move and extend over the hinge element 508 at variousflexion angles of the hinge 502. A cable plate 535 may be mounted on thesecond strut 520 and have an arm with adjustment holes 533. A route part558 is mountable to one of the adjustment holes to allow for selectivetensioning of the cable 522. The route part 558 diverts the cable overthe cable plate 535, and the cable 522 extends to the anchor 534.

According to this hinge assembly, the cable crosses over the hinge, suchthat as the hinge passes through an instantaneous center of the hinge,the cable switches from loading to unloading (increasing to decreasingin length). From this arrangement, the load increases from 90 degreesflexion up to approximately 30 degrees flexion, and then decreases inload from approximately 30 to 0 degrees to full extension, therebymimicking the load curve of FIG. 10.

As shown in FIG. 14, the orthopedic device 554 includes lower and upperframes 519, 521, extending from the first and second struts 518, 520,respectively. While in this embodiment the lower frame 519 includes ananterior portion 569, and the upper frame 521 likewise includes ananterior portion 571, the lower and upper frames can be modified toextend over the posterior leg rather than the anterior leg, as depicted.

Various straps are provided to counteract the lower and upper frames,and the load exerted by the dynamic loading component. Front strap 564having a pad 566, and rear strap 560 having a rear pad 562 are arrangedon the upper frame 521. An upper wrap 570 extends opposite the upperframe 521, whereas a wrap 556 extends generally circumferentially aboutthe lower leg from the dynamic loading component. A lower rear strap 568extends generally opposite the lower frame 519.

The orthopedic device generally provides a dual 3-point system femoralsupport. Counter force Fc1 is provided at the anterior portion 571 ofthe upper frame 521, followed by a counter force Fc2 at the rear strap560 with the front strap 564 resisting the rear strap 560. The lowerstrap 568 provides a counter force Fc4. The dynamical loading element538 provides a load or force Fc3 resisted by the other counterforces,which urges the tibia in a rearward, posterior direction while beingresisted by the aforementioned counterforces. The counter forces Fc1 andFc3 resist Fc2 resist one another, whereas the counter forces Fc2 andFc4 resists the counter force Fc3 to provide the dual 3-point system.The forces work in tandem to apply approximate forces on the femur andtibia while maintaining the brace on the leg.

FIG. 15 illustrates another hinge assembly or adjustment device 600 onan orthopedic device 654 providing a dual 3-point system as in theembodiment of FIG. 14. In this embodiment, however, the lower and upperframes 619, 621 have posterior portions 669, 671, respectively, over theposterior side of the leg, and the dynamic loading component 638 isarranged to be located on the distal posterior thigh but is arranged notto impinge the popliteal of the user. As with the embodiment of FIG. 14,he counter forces Fc1 and Fc3 resist Fc2 resist one another, whereas thecounter forces Fc2 and Fc4 resists the counter force Fc3 to provide thedual 3-point system.

The cable 622 is extended over the hinge element 608 and has a movementprofile 682 permitting movement over flexion to extension and so forth.The movement profile generally forms a “V” shape and substantiallyextends from anterior and posterior peripheral sides of the hingeelement 608 while the crest of the V-shape is anchored at the lowerguide 674. The hinge element 608 preferably is a low profile to permitthe cable 622 to sweep over the hinge element 608 during flexion withthe lower cable guide serving as the pivot point.

The arrangement of the orthopedic device is such that the dynamicloading component loads proximally above the knee has the advantage ofpreventing migration of the orthopedic device on the leg of the user. Asthe dynamic loading component urges a load above the knee at the femur,downward migration of the orthopedic device is minimized. The tendencyof distal migration is reduced with a posteriorly positioned femoralload versus an anterior positioned tibia load while a user is seatedgenerally at 90 degrees flexion. An anteriorly positioned tibia loadwill have the tendency to drive the orthopedic device downwardly anddistally the leg. An anti-migration strap 671 may be used for the lowerstrut 620 to keep the orthopedic device from migration, and the strap671 is arranged so as to rest along or above the belly of a user's calfto minimize sliding down the lower leg.

The hinge assembly 600 includes a hinge 602 that may be arranged inother embodiments described, and includes a hinge element 608 definedover the outer surface of the hinge 602. The hinge assembly 600 includesa cable 622 extending from a cable guide 674 on the first or lower strut618 or lower frame 619. The cable 622 preferably extends to an uppercable guide 674 on the second or upper strut 620 or the upper frame 621at inlet 675 generally located on the front or anterior side of thesecond strut 620. The cable 622 extends generally perpendicularlythrough a cable channel 676 defined by at least the upper cable guide674 and exits the cable guide 674 at the posterior side of the uppercable guide 674 at outlet 677 to extend to the dynamic loading component638.

In any of the embodiments described herein, selective preset tensioningof the cable may be achieved at the dynamic loading element. Asdiscussed more fully in U.S. provisional application No. 61/838,217,filed on Jun. 21, 2013, and incorporated herein by reference, thedynamic loading system may include a load-limiting clutch for tensioningthe ends of the pair of cables (from both sides of the orthopedicdevice) extending into the dynamic loading element.

As shown in FIGS. 17A-17C, the second strut or upright 620 to theorthopedic device includes a cutout 688 corresponding to the upper cableguide 674 and corresponding channel 678. The cutout 688 is generallyarranged in the saggital plane and not the coronal plane. In analternate embodiment, the cutout may be provided on the first strut orupright 618 when the dynamic loading component is urged against thetibia.

MCL injuries are often concurrent with ACL injury and thereforereduction of medial/lateral compression minimizes contact pressure onthese injured regions. As shown in FIG. 16A, if the cutout is notpresent, the cable load is mainly in the coronal plane with the hingeassembly and orthopedic device loading in the coronal plane instead ofloading the posterior femur in the saggital plane shown in FIG. 16B.FIG. 16A shows how the cable 622 must extend about the pair of secondstruts 620A, 620B and the majority of loading occurs in the coronalplane as depicted by the coronal force component 684A being greater thanthe saggital force component 684B. FIG. 16B shows how the cutout 688allows for more loading in the saggital plane by the schematic 686. Thesaggital force component 686B is greater than the coronal forcecomponent 686A.

FIGS. 17A-17C illustrate how peak cable tension occurs as the cablepasses over the instantaneous center of the hinge 602 and relative topivot points 604, 606. In this embodiment, the upper guide 674 isarranged forward of the cutout 688 to enhance movement of the cablealong the saggital plane. Each of the first and second struts 618, 620include a plurality of openings for mounting the cable, such as by thecable guide. At extension at θ_(A), the cable length A is less than thecable length B at flexion with the peak angle θ_(B), such as 30 degrees.After the peak angle θ_(B), subsequent increased flexion angles θ_(C)result in a shortening of the cable length C. As shown, the cabletension relaxes toward extension and towards flexion before and afterreaching the peak angle θ_(B). The cable length generally has therelationship wherein cable length A<cable length B>cable length C.

While the foregoing embodiments have been described and shown,alternatives and modifications of these embodiments, such as thosesuggested by others, may be made to fall within the scope of theinvention. While the orthopedic device has been described in a kneebrace, it will be understood that the principles described may beextended to other types of orthopedic devices.

The invention claimed is:
 1. An orthopedic device arranged to articulateduring flexion at a plurality of angles between extension at 0 degreesand a maximum flexion at 135 degrees, the device comprising: a firstframe; a dynamic loading component connected to the first frame andlocated on an anterior or posterior side of the orthopedic device, avariable distance defined between the dynamic loading component and thefirst frame; an adjustment device arranged to regulate a length of atleast one elongate element and move the dynamic loading component towardthe first frame by reducing a length of said variable distance, the atleast one elongate element connecting to a lateral or medial side of thefirst frame and coupling the dynamic loading component thereto, theadjustment device arranged to create peak tension in the at least oneelongate element at a peak angle between extension and maximum flexionof the orthopedic device and generally diminish in tension from the peakangle toward extension and flexion; a second frame and a hinge assemblyconnecting the first and second frames to one another; wherein theadjustment device connects to or across the hinge such that the dynamicloading element is urged inwardly toward the first frame as the kneeundergoes flexion, the at least one elongate element freely moving fromgenerally anterior and posterior peripheral sides of the hinge over amovement profile.
 2. The orthopedic device of claim 1, wherein the hingehas a substantially flat hinge plate over which the at least oneelongate element freely slides.
 3. The orthopedic device of claim 1,wherein the at least one elongate element includes first and secondelongate elements each extending from first and second sides,respectively, of the orthopedic device, wherein the adjustment device isadapted for simultaneously regulating the length of the first and secondelongate elements.
 4. The orthopedic device of claim 1, wherein the atleast one elongate element extends laterally from the dynamic loadingcomponent to at least one of the lateral or medial sides of the firstframe, the orthopedic device further comprising a guide arranged tolongitudinally route the at least one elongate element along the firstframe toward the hinge.
 5. The orthopedic device of claim 1, wherein thefirst frame defines a cutout providing a clearance through a width ofthe first frame and generally opposite the dynamic loading component,the at least one elongate element arranged to articulate within thecutout (and toward the dynamic loading component.
 6. The orthopedicdevice of claim 5, further comprising a first guide located on the firstframe and opposite the dynamic loading component, the first guide havinga channel defining first and second ends through which the at least oneelongate element is routed in a curved manner between the first andsecond ends.
 7. The orthopedic device of claim 6, further comprising asecond frame and a hinge connecting the first and second frame, and asecond guide located on the second frame, the at least one elongateelement arranged to extend from the second guide to the first guide andover the hinge.
 8. The orthopedic device of claim 7, wherein the secondframe defines a plurality of openings along its length for selectiveplacement of the second guide to establish an initial tension in the atleast one elongate element at flexion of the orthopedic device.
 9. Theorthopedic device of claim 1, wherein the peak load in the at least oneelongate element occurs generally when the orthopedic device is inflexion in the range of 10-40 degrees at peak angle.
 10. The orthopedicdevice of claim 9, wherein the tension in the at least one elongateelement substantially diminishes from and near the peak angle and slowlytapers approaching either maximum flexion or full extension.
 11. Theorthopedic device of claim 1, wherein the dynamic loading component isarranged at a distal posterior thigh region of a user and above a hingeof the orthopedic device.
 12. The orthopedic device of claim 1, whereinthe at least one elongate element extends toward the dynamic loadingcomponent at an oblique angle generally more towards a saggital planethan a coronal plane.
 13. The orthopedic device of claim 1, wherein thefirst frame defines a cutout section forming a clearance within thewidth of the first frame and sized to permit the at least one elongateelement to move therethrough.
 14. A method for providing variableassistance during gait, the method comprising the steps of: providing anorthopedic device on a leg of a user, the orthopedic having a dynamicloading component adapted to apply pressure against a leg of a user;urging a load by the dynamic loading component against a user's legduring an initial stage of flexion of a leg; increasing the load to apeak load corresponding to a peak angle of flexion; diminishing the loadafter reaching the peak angle of flexion as the leg continues to undergoextension.
 15. The method of claim 14, further comprising the step of:initially setting the degree of force by an adjustment device before auser's knee undergoes extension.
 16. The method of claim 14, wherein theat least one elongate element extends toward the dynamic loadingcomponent at an oblique angle generally more towards a saggital planethan a coronal plane.
 17. The method of claim 14, wherein the peak loadin the at least one elongate element occurs generally when theorthopedic device is in flexion in the range of 10-40 degrees at peakangle.
 18. An orthopedic device, comprising: a first frame defining acutout forming a clearance through the width of the first frame; asecond frame; a hinge assembly connecting the first and second frames; adynamic loading component connected to the first frame and located on ananterior or posterior side of the orthopedic device, a variable distancebeing defined between the dynamic loading component and the first frame;an adjustment device arranged to regulate a length of at least oneelongate element between the adjustment device and the first frame andmove the dynamic loading component toward the first frame by reducing alength of said variable distance; a first guide connected to the firstframe and defining a channel through which the at least one elongateelement extends; a second guide connected to the second frame andsecuring an end of the at least one elongate element thereto, the atleast elongate element extending from the second guide and over thehinge assembly to and through the first guide to articulate within thecutout and secure at one end to the dynamic loading component, thedistance of the at least one elongate element between the first andsecond guides is at a maximum when the hinge assembly is at a flexionangle within the range of 10 to 40 degrees.